This application is based on Patent Application No. 2001-244890 filed Aug. 10, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a socket for a semiconductor device used for testing the semiconductor device.
2. Description of the Related Art
Semiconductor devices to be mounted to an electronic equipment or others are subjected to various tests prior to being mounted so that potential defects thereof are removed. Such tests are carried out in a non-destructive manner by the application of voltage stress in correspondence to thermal and mechanical environmental tests, the high-temperature operation or the high-temperature reservation of the above-mentioned various tests. It has been said that a burn-in test is effective for removing integrated circuits having infant mortality failures, in which a performance test is carried out under a high-temperature condition for a predetermined period.
A socket for a semiconductor device used for such a test is disclosed, for example, in Japanese Patent Application laid-open No. 10-302925 (1998), wherein the socket is disposed on a printed circuit board having an input/output section for supplying a predetermined test voltage to the semiconductor device to be tested and issuing an abnormality detection signal generated therefrom, representing a short-circuit accident or others.
The semiconductor device-socket includes, for example, a positioning member having an accommodation portion in which a semiconductor element as the semiconductor device is mounted, a contact deviation member 2 disposed to be reciprocated in the predetermined direction as shown in FIG. 15, while supporting the positioning member and causing one movable contact piece of a contact terminal described later to be closer to and farther from the other movable contact piece, a socket body 6 disposed on a printed circuit board to accommodate the contact deviation member 2 in a movable manner (see FIG. 17A), and a cover member (not shown) for converting an operating force applied thereto and transmitting the same to the contact deviation member 2 via a drive mechanism not shown.
As shown, for example, in FIGS. 17A, 17B and 17C, a group of terminals of the printed circuit board are connected to proximal ends 4B of terminals in a plurality of contact terminals 4ai (wherein i=1 to n; n represents a positive integer) provided in the socket body 6.
The respective contact terminal 4ai is provided in correspondence to each of electrode sections 8a on a semiconductor element 8 mounted to the positioning member, and consists of the proximal terminal 4B and a pair of movable contact pieces 4F and 4M coupled to the terminal 4B to selectively nip the respective electrode section 8a of the semiconductor element 8 for the electrical connection therewith as shown in FIG. 17C.
The pair of movable contact pieces 4F and 4M of the thin plank-type contact terminal 4ai is inserted into the respective contact accommodation portion 2a as shown in FIGS. 15 and 16. The respective contact accommodation portion 2a is formed by partitioning the interior of the contact deviation member 2 with partitioning walls 2Wa extending in the moving direction of the contact deviation member 2 shown by an arrow C. Note that FIGS. 15 and 16 illustrate a released state in which the pair of movable contact pieces 4F and 4M of the contact terminal 4ai are apart from each other.
A plurality of partition walls 2Wt extending transverse to the partition walls 2Wa are disposed at a predetermined distance from each other above the contact accommodation portions 2a. Thereby, a plurality of relatively small generally square openings are defined at an upper end of the contact deviation member 2. Directly underneath the respective partition wall 2Wt, a groove engageable with part of the side portion of the movable contact piece 4M is formed.
The respective contact terminals 4ai, each having the opposite pair of movable contact pieces 4F and 4M, are arranged in a line so that the movable contact pieces 4F in the one contact terminal 4ai is adjacent to the movable contact piece 4M of the other contact terminal 4ai. 
When the contact deviation member 2 moves from one state shown in FIGS. 17A and 18A to another state in direction as shown by an arrow in FIGS. 17B and 18B, the pair of movable contact pieces 4F and 4M move from a position shown by a chain double-dashed line to another position shown by a solid line due to the movement of the movable section 4M accompanied with the movement of the respective groove, whereby both the movable contact pieces 4F and 4M are further away from each other. In this state, the semiconductor element 8 is mounted. Or the semiconductor element 8 having being tested is removed from the socket body 6.
In this connection, the mounting of the semiconductor element 8 may be carried out by an automated machine or by a hand of the operator, during which the respective electrode sections 8a of the semiconductor element 8 are guided by all the peripheral edges of openings formed at the upper end of the contact deviation member 2 and accommodated into the contact accommodation portions.
On the other hand, when the contact deviation member 2 moves in the direction as shown in FIG. 18C by an arrow, the pair of movable contact pieces 4M and 4F moves from a state shown by a chain double-dashed line in which both the movable contact pieces are away from each other to another state shown by a solid line in which both the movable contact pieces are closer to each other to nip the electrode section 8a of the semiconductor element 8.
There is a risk in that, between adjacent two contact terminals 4ai, a movable contact piece 4M in the one contact terminal 4ai is brought into contact with another movable contact piece 4F in the other contact terminal 4ai because an opening amount between the pair of movable contact pieces 4M and 4F individually varies between distal ends thereof due to the manufacturing error as shown in FIGS. 17B and 18B by a solid line. In that case, If a test signal is issued from the printed circuit board to the pair of movable contact pieces 4F and 4M under such a condition, there may be a short-circuit accident. A contact accident of this kind would become significant as the density of the electrode section 8a of the semiconductor element 8 increases while ensuring a necessary opening amount between the pair of movable contact pieces 4M and 4F.
To avoid such an accident, it would be thought that the opening amount between the pair of movable contact pieces 4F and 4M is selected to be smaller than the predetermined opening amount by taking the variance thereof into account.
The above countermeasure, however, is defective because the opening amount between the distal ends of the pair of movable contact pieces 4F and 4M is insufficient to become a factor to cause an undesirable faulty attachment of the electrode section 8a of the semiconductor element 8. Thus, it is inadvisable to do so.
When the semiconductor element is mounted to the accommodation portion in the positioning member, there may be a case wherein the terminal of the semiconductor element does not fit in the contact accommodation portion 2a but rides on the outside of the entire outer periphery of the contact accommodation portion 2a due to the manufacturing error. Thereby, the above-mentioned burn-in test may not be quickly carried out.
In view of the above problems, an object of the present invention is to provide a socket used for testing a semiconductor device, capable of avoiding the mutual contact of movable contact pieces in adjacent contact terminals with each other as well as ensuring the maximum opening amount between both the movable contact pieces in the contact terminal.
To achieve the above object, a socket for a semiconductor device, comprising a plurality of contact terminals disposed in a socket body for accommodating the semiconductor device having a plurality of contact terminals, each contact terminal having a pair of movable contact pieces for selectively nipping each of the terminals in the semiconductor device to carry out electrical connection, a contact deviation member provided in the socket body in a movable manner, for causing the contact terminal to carry out the electrical connection/disconnection by selectively moving one of the pair of movable contact pieces to be closer to or farther from the other, and a position-restricting means formed in the contact deviation member, for restricting a position of one of the pair of movable contact pieces relative to another movable contact piece in the adjacent contact terminal when the former movable contact piece is farther from the other movable contact piece in the same pair and closer to the latter movable contact piece in the adjacent contact terminal, so that the relative position of the former movable contact piece is restricted to the latter movable contact piece.
A plurality of the position-restricting means may be disposed opposite to portions of a partition wall for individually dividing rows of the contact terminals in the contact deviation member, in which portion holds one of the movable contact pieces.
The portion of the partition wall for holding the one of the movable contact pieces may be provided with an engaging groove for the engagement with the movable contact pieces.
The position-restriction means may be a projection adapted such that when one movable contact piece is farther from the other movable contact piece in the same contact terminal and closer to another movable contact piece in the adjacent contact terminal, the projection abuts to the back surface of the latter movable contact piece and forms a gap between both the contact pieces being closer to each other.
A slope may be continuously formed along a boundary between the entire outer periphery of a contact accommodation portion for accommodating the pairs of movable contact pieces of the plurality of contact terminals and the placement region for placing the semiconductor device, for introducing the terminals of the semiconductor device just before being placed into the contact accommodation portion.
As apparent from the above description, according to the socket for a semiconductor device, since the position-restricting means is formed in the contact deviation member to restrict, when one movable contact piece in one contact terminal is away from the other movable contact piece in the same contact terminal, the relative position of the one movable contact piece to another movable contact piece in the adjacent contact terminal, it is possible to avoid the mutual contact between the movable contact pieces adjacent to each other, as well as ensuring the maximum opening amount between both the movable contact pieces in the contact terminal.
Since the slope is continuously formed along the boundary between the entire outer periphery of the contact accommodation portion and the placement region for placing the semiconductor device, it is possible to assuredly mount the semiconductor device.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.